An LDPC (Low Density Parity Check) code has the high error correction capability and has been recently adopted widely to a transmission system including satellite digital broadcasting such as DVB (Digital Video Broadcasting)-S.2 performed in Europe (for example, refer to Non-Patent Literature 1). In addition, adopting of the LDPC code to next-generation terrestrial digital broadcasting such as DVB-T.2 has been examined.
From a recent study, it is known that performance near a Shannon limit is obtained from the LDPC code when a code length increases, similar to a turbo code. Because the LDPC code has a property that a shortest distance is proportional to the code length, the LDPC code has advantages of a block error probability characteristic being superior and a so-called error floor phenomenon observed in a decoding characteristic of the turbo code being rarely generated, as characteristics thereof.